Homeland Security Secretary Jeh Johnson said he is concerned about drones threatening 2016 presidential candidates, The Hill reports.

Said Johnson: “It is definitely an issue. This is something that U.S. NORTHCOM, me, Secret Service, Capitol Police, Metro police here in the Washington, D.C. area, we need to refine our protocols for airborne stuff in the national capital region to deal with what we’re referring to as the low and slow stuff.”